DmSTM-1. NG-SDH Multiplexer.
NG-SDH Multiplexer

The DmSTM-1 is a modular multiplexer for new generation SDH networks (NG-SDH). The basic unit composed of chassis, central processing unit and power source permits the introduction of two aggregate interface cards and up to three tributary interface cards. It modularity facilitates the expansion of the network and the support of new services.


The configuration facilities ensure compatibility and full interoperability with the vast majority of SDH/NG equipment from other manufacturers. Permits multiplications of up to 63 2Mbit/s tributaries when equipped with three DmSTM-1 TR-24E1 tributary interface cards. Can also be equipped with STM-1, 34/45Mbit/s tributary interfaces and Ethernet.


  • Can operate as a terminal multiplexer or add/drop, even as a ring head
  • Provides external synchrony outputs and inputs, alarms, V.11 interface, voice channel, serial and Ethernet
  • Supports hot-swap in all modules and redundant power source
  • Local and remote equipment management
  • Compact design, permits installation in a 19 rack using 2U (height units)


STM-1 Interfaces

  • Optical STM-1 with a range of connector and reach options, including bidirectional WDM G.703 electrical STM-1 with CMI codification


Tributary Interfaces

  • Tributary card with eight 10/100Mbit/s Ethernet ports. Conducts Ethernet signal mapping over SDH.
  • Offers virtual concatenation, GFP and LCAS encapsulation facility.
  • Tributary cards with 24 75ohm or 120ohm G.703 2Mbit/s interfaces available in two TELCO 50 pin connectors. The TELCO connector permits connection to DID using twisted pair, without the need for an adaptor or connector patch panel. Equipped with three TR-24E1 tributary interfaces that permits the mapping of up to 63 2Mbit/s tributaries. The 2Mbit/s tributaries are mapped in the asynchrony mode in any TU-12/TUG-3
  • Tributary card with a 75ohm G.703 electric 34/45Mbit/s interface conducts 34Mbit/s or 45Mbit/s tributary mapping in the STM payload (VC-3)
  • Tributary card with 75ohm G.703 electric STM-1 or optical STM-1. Cross-connect capacity for 1xVC-4, 3xVC-3 and 63xVC-12 aggregate interfaces.


Protection Options

  • Sub-Network Connection Protection (SNCP)
  • 1+1 Multiplex Section Protection (MSP)



  • Two input interfaces and output interfaces for 2MHz G.703 synchrony
  • Synchrony can be obtained from any aggregate port, tributary, external or internal synchrony input (holdover and free-running)


External Alarms

  • Externalization of the alarm due to the dryness and two independent outputs
  • Four external alarm inputs


Power Supply

  • Power supply with automatic AC (93 to 253V) and DC (36 to 72V) selection with the possibility of redundancy and hot-swap support



  • ALS – Automatic Laser Shutdown, increases security in the installation and maintenance of optical links
  • Service channel for connection to a common telephony device
  • Access to user channels and DCC in V.11 interface
  • Local and remote loopback in STM-1 aggregates and tributaries
  • Oversight of failures and performance
  • Light indicators of the state of equipment, failures, alarm and tests
  • Internal router that can operate with Frame Relay or PPP
  • Remote (Ethernet and in-band) or local management via Terminal (RS-232)
  • Permits the management of remote equipment
  • Remote upgrade of firmware
  • Excellent cost-benefit ratio, easy installation and configuration